feat: add element inspector with chat integration

- Implement element inspector tool for preview iframe with hover/click detection
- Add inspector panel UI to display element details and styles
- Integrate selected elements into chat messages for reference
- Style improvements for chat messages and scroll behavior
- Add inspector script injection to preview iframe
- Support element selection and context in chat prompts
-Redesign Messgaes, Workbench and Header for a more refined look allowing more workspace in view

app/styles/index.scss

@@ -11,6 +11,7 @@ html,
 body {
   height: 100%;
   width: 100%;
+  background-color: var(--bolt-elements-bg-depth-1);
 }
 
 :root {